1. Field of the Invention
The present invention relates to measuring devices, and more particularly pertains to a new and improved measuring device which combines the functions of a plurality of protractors and rulers into a single easily manipulated device. In order to accurately construct or measure triangles before the advent of the present invention, it was necessary to repeatedly manipulate a single ruler and a protractor. Needless to say, this procedure is tedious and time consuming. Additionally, these repeated manipulations introduce errors. In order to overcome these problems and to provide an easily operated measuring instrument for performing a variety of geometrical functions, the present invention provides a triangular measuring device which includes three adjustable legs each provided with a protractor for quickly measuring or constructing a triangle of any desired dimensions.
2. Description of the Prior Art
Various types of measuring devices are known in the prior art. A typical example of such a measuring device is to be found in U.S. Pat. No. 115,318, which issued to E. Hickman on May 30, 1871. This patent discloses a measuring device having a plurality of relatively slidable interconnected linear scales with one of the scales including a protractor. The various linear scales are arranged for measuring various trigonometric functions such as radius, sine, cosine, tangent, cotangent and secant of a geometric figure. U.S. Pat. No. 830,727, which issued to E. Long on Sept. 11, 1906, discloses a combined square, bevel and protractor which utilizes two pivotally connected L-shaped scales, with one of the scales provided with a protractor. U.S. Pat. No. 1,730,852, which issued to W. Jenny on Oct. 8, 1929, discloses a measuring device for measuring the angles and hypotenuse of a triangle. A pair of perpendicular linear scales are provided with a third pivotal leg which is slidably mounted on one of the perpendicular linear scales. A protractor allows the angle of the pivotal leg to be determined. U.S. Pat. No. 2,517,264, which issued to H. Wake on Aug. 1, 1950, discloses a measuring device which utilizes a pair of perpendicular linear scales each provided with a track which slidably receives a protractor for linear adjustment therealong. A pivotal leg is mounted on each protractor. U.S. Pat. No. 4,208,804, which issued to B. Lundin on June 24, 1980, discloses a ruler for dividing a distance into a predetermined number of equal parts. The ruler includes a linear scale with a plurality of numbered scales having a common zero point. A plurality of holes are provided along the ruler for plotting an optional division of an auxiliary distance. The ruler has one end portion mounted in an arcuate track of a protractor.
While the above mentioned devices are suited for their intended usage, none of these devices disclose a measuring device formed in the configuration of a triangle having three relatively slidable legs each provided with a protractor. Inasmuch as the art is relatively crowded with respect to these various types of measuring devices, it can be appreciated that there is a continuing need for and interest in improvements to such measuring devices, and in this respect, the present invention addresses this need and interest.